Deep-Sea Biology and Adaptations

Lecture 1 - General Concepts

• Terrestrial and aquatic animals use substrate to avoid predators or capture prey. Methods include hiding under, or in the substrate, or mimicking it.
• Animals that camouflage themselves do so in three ways: colour matching, structural matching, or a combination of both.
• Crypsis is a form of camouflage that involves blending into the environment.
• Animals can reduce conspicuousness in habitats without substrate by manipulating or reflecting light, becoming transparent. There are two forms, partial and total transparency.

Camouflage in Animals

• Animals use various methods to avoid detection by predators or prey.
• Combination of colour matching and structural matching in some animals allows for effective camouflage.
• These strategies can work together for enhanced effectiveness.
• Example creatures such as Flounder and Cigar wrasses utilize a combination of colour and structure for effective camouflage.

Transparency in Animals

• Some animals use transparency as a defence mechanism, it minimizes scattering and reflection of light, thus passing light through the organism.
• Transparency can be partial, affecting parts of the organism or, complete, with the whole organism being transparent.
• Transparency is most common in aquatic environments, particularly in deep sea environments.

Lecture 2 - Bioluminescence

• Bioluminescence is the production and emission of light by a living organism. It is a chemical reaction that does not produce much heat.
• Bioluminescence is found in a wide range of organisms, including invertebrates (e.g., fireflies) and some vertebrates, from bacteria and fungi to deep-sea creatures.
• Most bioluminescent organisms are marine, being found in the pelagic, mesopelagic and benthic zones.
• The purpose of bioluminescence in different organisms varies, including attracting prey, defense, camouflage, and communication.
• A chemical reaction that does not produce a lot of heat but instead produces light.

Lecture 2 - Further Details About Bioluminescence

• Bioluminescence is a chemical reaction that produces light in organisms.
• This reaction is highly efficient compared to other processes in organisms and it produces little to no heat.
• Bioluminescence occurs in a variety of organisms from bacteria to deep-sea fish.
• Bioluminescence is important to organisms that live in the dark such as the deep sea and those above it such as fireflies.

Lecture 3 - Deep-Sea Adaptations

• Deep-sea animals face challenges such as high pressure, cold temperatures, and the absence of light.
• These animals have evolved adaptations to cope with these factors, including low metabolic rates and specialized protein structures.
• Deep-sea animals often have large mouths and flexible digestive tracts. This is because of their limited food access.
• Some creatures have adapted to eat anything they can find and a higher proportion of fat to meet metabolic demands.
• Some species have adapted eyes that can detect light in very low light levels.

Lecture 3 - Deep-Sea Adaptations (Continued)

• Deep-sea animals have adaptations that make them more suited to their environment like the size and composition of their bodies.
• Their structure adapts to the high pressure.
• Many adaptations are related to minimizing metabolic cost for deep-sea animals and conserving energy.
• E.g. - they have lower metabolic rates, low muscle mass, adaptations in their skin composition, and teeth

Lecture 3 - Deep-Sea Environment

• Deep-sea environments feature a significant diversity of life and unique adaptations.
• Organisms in these environments adapt to low-nutrient levels and deep conditions.
• Chemoautotrophic bacteria in hydrothermal vents are a vital part of the food web, converting chemicals into energy in the absence of light.
• Organisms can potentially survive without light because the basis of the food web in deep-sea vents comes from chemical processes, thus requiring different adaptations to the environment.

Lecture 1 - Bony Fishes

• Approximately 30,000 species of bony fishes exist.
• Diet, activity patterns, and environmental conditions influence feeding strategies in bony fishes.
• Bony fishes exhibit varied methods of feeding, such as sit-and-wait strategies and active searching strategies.
• The methods of feeding vary widely - some consume plankton and others large animals.
• Sensory capabilities and propulsion methods help fishes locate and catch prey.

Lecture 1 - Cartilaginous Fishes

• Cartilaginous fishes have existed for over 400 million years and encompass sharks, skates, rays and elephant sharks.
• Their diverse environments have resulted in variation in types of feeding and different adaptations for those environments.
• Their varied diet often reflects the type of environment an individual species lives in.
• Examples of feeding strategies in different cartilaginous fish species.

Lecture 1 - Feeding Strategies

• Feeding strategies in fish vary greatly depending on species and environment.
• Sit-and-wait strategies are common in some species, whereas others employ active strategies.
• This is influenced by environmental factors that affect the fish's ability to locate food or hunt for it.
• Characteristics of both sit and wait predators and active predators are discussed.

Lecture 2 - Audiograms and Hearing

• The ability of animals to hear in different environments.
• Hearing sensitivity and frequency ranges vary among species.
• Specialization in certain frequencies allows certain animals to differentiate between sounds better in their environments.
• Sound waves in different environments such as water may differ, and thus hearing sensitivity has evolved differently in many different species.

Lecture 2 - Visual and Other Sensory Systems

• Visual attraction, use of lures, and how organisms utilize bioluminescence in the visual spectrum for communication, feeding, and defense.
• Importance of bioluminescence in the deep ocean, and how visual attraction can be used in the identification of different species.
• Details of other sensory systems in animals (e.g., taste, smell, touch, electroreception) and how these interact.
• How humans utilize sensory systems in animals for conservation work and animal welfare in general.

Lecture 2 - Electroreception

• Electroreception, both active and passive, is important in detecting electric signals in the environment (electrical fields).
• There are variations in electroreception among species, and this ability allows animals to find food or avoid predation more easily.
• The intensity and sensitivity of electroreception are highly specialized for different species.
• This allows animals to locate food in the dark, avoid predation or find individuals of the same species.

Lecture 2 - Detection of Bioluminescence

• The use of bioluminescence signals for different species of animals such as deep-sea fish.
• This involves detecting different intensities of light for different purposes or needs of the animal.

Lecture 3 - Metabolic Scope

• Metabolic scope encompasses a range from resting and base metabolic rate to maximal metabolic rate.
• Metabolic rates reflect the balance between energy demands and production and thus metabolic scope reflects the various ways of handling environmental pressures, i.e. temperature changes.
• Muscle type and function, such as red and white muscle, impact metabolic demands.
• Metabolic requirements vary greatly with species size, lifestyle, and environment.

Lecture 3 - Other Adaptations

• Detailed descriptions of adaptations like giant mouth, inward facing teeth, bioluminescence etc.
• There are wide-ranging variations in adaptations, and these adaptations relate to different aspects of an animal's life such as finding food, reproduction, and defense from predation.
• Differences in adaptations based on the specific roles animals take in their respective unique environment.

Lecture 3 - Impact of Climate Change

• Climate change is having an impact on many animals and these impacts will cause problems in their environment.
• Changing weather patterns are expected to impact animals significantly.
• Changes will likely impact the ability of organisms to effectively adapt and survive in their environment.

Lecture - Fish Kills

• Fish kills are typically associated with a combination of events, but usually the root cause relates to an excess or deficit in oxygen.
• An increase in oxygen demand is often the root cause of a fish kill.
• These kills occur in areas with large volumes of fish.

Lecture - Mollusk Reproduction

• Many mollusks employ different reproduction strategies, reflecting differences in their environment and how their adaptations work to counteract pressures.
• There is a significant amount of diversity in the ways in which mollusks reproduce.
• Examples of adaptation include strategies for avoiding desiccation and methods to protect eggs.

Lecture - Osmoregulation

• Understanding how organisms regulate water and salt levels in their bodies is important when studying their characteristics.
• Adaptations and strategies vary between different animal types regarding how they handle these.
• Osmoregulation is a critical aspect of survival for aquatic organisms, with different strategies (e.g. osmoconformity and osmoregulation) varying between species to ensure survival.

Lecture - Endocrinology and Behaviour

• Endocrinology plays a significant role in animal behaviour, with hormones influencing a range of activities, ranging from reproductive behaviours to responses to stress. Understanding the role of hormones can inform conservation management by informing how hormones and endocrine signalling can contribute to survival and reproduction.
• Different types of hormones regulate different behaviours or actions in animals.
• Hormones associated with behavioural responses are discussed, along with the concept of endocrine disruption.

Lecture - Hormone Monitoring

• Non-invasive hormone monitoring in animals is increasingly used in research.
• The use of methods like analysis of faeces provides valuable data on an animal's health.
• The use of urine and faecal products helps monitor hormone levels in animals by providing broader, more holistic insights into overall patterns.
• The methods have advantages over extracting blood samples.

Lecture - Reproductive Endocrinology

• Reproduction is influenced by hormonal processes driven by the hypothalamus, pituitary, and gonadal axis.
• Reproduction-related hormones have different cycles, and this can provide insights on the reproductive cycles of organisms.
• Different types of hormones influence behaviours or regulate different behaviours.
• Reproduction-related hormones and their effect on organisms are discussed.

Lecture - Whale Response To Boat Activity

• Whale behaviour and responses to boat activity may impact reproductive success, survival, and overall population health.
• Endocrine disruption by human activities can negatively influence whale behaviour and physiology.
• Anthropogenic noise, pollution and stress may impact their communication and reproductive success, respectively.

End of Notes

This quiz explores the unique adaptations of deep-sea animals and the challenges they face in their dark, high-pressure environment. Questions cover topics such as feeding mechanisms, sensory capabilities, and the role of bioluminescence in survival. Test your knowledge on these fascinating creatures and their ecological significance.